Article
Chemistry, Organic
Kaizhi Li, Yixin Lu
Summary: Enantioselective gamma-addition of readily available alpha-substituted nitroacetates to allenoates has been achieved, providing a straightforward asymmetric synthesis of optically enriched alpha,alpha-disubstituted alpha-amino acid precursors. The reaction proceeds efficiently with high yields and good to excellent enantioselectivities in the presence of amino acid-derived phosphine catalysts, forming products containing a tetra-substituted stereogenic center.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Organic
Ke Li, Zhenjie Gan, Er-Qing Li, Zheng Duan
Summary: A novel phosphine-catalyzed (4 + 2) cyclization reaction has been reported for the generation of functionalized dihydropyran skeletons from electron-deficient conjugated dienes and enones. Mechanistic investigation reveals the formation of a new phosphonium zwitterion, which undergoes consecutive reactions. An asymmetric variant has also been developed through efficient and economical chiral phosphine catalysis.
Article
Chemistry, Physical
Sha Hu, Jiale Wu, Zuolin Lu, Jiaqi Wang, Yuan Tao, Meifen Jiang, Fener Chen
Summary: This study presents a time-economical method for the synthesis of diarylacetates through the TfOH-catalyzed arylation of alpha-aryl-alpha-diazoesters with arenes, offering good yields with broad substrate scope, excellent functional group compatibility, and mild reaction conditions. Additionally, a new mechanism for the arylation reaction of alpha-aryl-alpha-diazoesters with arenes under TfOH catalysis is proposed.
Article
Chemistry, Organic
Dongqiu Li, Fang Cheng, Yuhai Tang, Jing Li, Yang Li, Jiao Jiao, Silong Xu
Summary: The method described involves a phosphine-catalyzed internal redox [4 + 2] annulation of 1,4-enynoates with electron-deficient alkenes, resulting in the efficient synthesis of highly functionalized cyclohexenes with exclusive regioselectivity and high diastereoselectivity under mild conditions.
Article
Chemistry, Multidisciplinary
Yu-Feng Zhang, Jia-Huan Wang, Ning-Yuan Yang, Zheng Chen, Li-Lei Wang, Qiang-Shuai Gu, Zhong-Liang Li, Xin-Yuan Liu
Summary: A copper-catalyzed enantioconvergent radical C-N cross-coupling of alkyl halides with sulfoximines (as ammonia surrogates) under mild conditions has been developed using a chiral anionic N,N,N-ligand with a long spreading side arm. This method efficiently and selectively synthesizes a range of α,α-disubstituted amino acid derivatives. The synthetic utility of the strategy has been demonstrated through the elaboration of the coupling products into different chiral α-fully substituted amine building blocks.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Wentao Zhong, Meng Li, Yangbin Jin, Huanfeng Jiang, Wanqing Wu
Summary: Here, a straightforward method for synthesizing 2,5-disubstituted selenophenes has been developed. The method utilizes easily accessible terminal alkynes and elemental selenium, and features high atom- and step-economy, excellent regioselectivity, and good functional group tolerance. Control experiments suggest a possible mechanism involving Glaser coupling reaction, H2Se insertion, and subsequent cyclization. Additionally, the newly formed products can be further converted to diverse conjugated selenophene-based derivatives, demonstrating their potential applications in organic synthesis and materials science.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Xue Song, Yangxu Chen, Fangfang Lu, Kai Zhang, Chenxia Yu, Tuanjie Li, Changsheng Yao
Summary: A facile NHC-catalyzed [2 + 4] annulation of allenoates with 2,3-dioxypyrrolidine derivatives has been discovered, providing a new approach for the synthesis of highly substituted pyranopyrrole compounds with moderate to good yields, high atom economy, and mild reaction conditions.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
Article
Chemistry, Organic
Fei Wang, Yoshihiro Nishimoto, Makoto Yasuda
Summary: This article describes a reaction method catalyzed by indium trihalide, which can insert diazo esters into carbon-halogen bonds, forming new carbon-halogen bonds and elongating the carbon chain.
Article
Chemistry, Organic
Fangfang Lu, Yangxu Chen, Xue Song, Chenxia Yu, Tuanjie Li, Kai Zhang, Changsheng Yao
Summary: A successful NHC-catalyzed [2+4] cyclization reaction was developed to synthesize highly substituted 4H-pyran derivatives with cheap and easily available starting materials, mild reaction conditions, moderate to excellent yields, and high atom economy.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Guo-Ke Zhang, Shu-Fang Wu, Chen Zhong, Yu-Qi Liu, Da-Hua Wang, Yu-Chen Zhang, Feng Shi
Summary: A copper-catalyzed alpha,beta-regioselective (2+4) cycloaddition of propargylic esters with o-hydroxyphenyl substituted secondary phosphine oxides (SPOs) was established, which afforded phosphorus-containing six-membered heterocycles in high yields. This reaction not only represents the first alpha,beta-regioselective (2+n) cycloaddition of propargylic esters via the intermediates of copper-allenylidenes, but also represents the first application of o-hydroxyphenyl substituted SPOs as 1,4-dinucleophiles in (2+4) cycloadditions.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Xiaohu Li, You Huang
Summary: A phosphine-catalyzed cascade (2+3)/(2+4) cyclization reaction has been developed for the synthesis of chromeno[4,3-b]pyrrole derivatives. This method provides good yield, excellent chemoselectivity and diastereoselectivity under mild conditions, resulting in compounds containing three contiguous stereogenic centers.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Organic
Dongqiu Li, Fang Cheng, Yuhai Tang, Jing Li, Yang Li, Jiao Jiao, Silong Xu
Summary: In this study, we describe a DABCO-catalyzed [4 + 2] annulation reaction between 5-methylenehex-2-ynedioates and electron-deficient olefins, which leads to the formation of functionalized cyclohexadienes in good yields under mild reaction conditions. The incorporation of the beta- and epsilon-carbons of the substrates for C-C bond formation represents a novel reactivity different from previous reports. It is believed that the annulation proceeds through a domino cyclization initiated by a cross Rauhut-Currier reaction.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Maying Yan, Lei Xiao, Jiangkun Xiong, Lvnan Jin, Douglas W. Stephan, Jing Guo
Summary: The B(C6F5)(3)-catalyzed transesterification of a series of 3-alkenyl-oxindoles and other unsaturated tert-butyl esters with aryl-diazo esters is reported. This protocol is facile and generally high yielding proceeding under mild conditions and is remarkably chemoselective leaving the C=C bonds intact.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Applied
Fernando Herrera, Pablo Esteban, Amparo Luna, Pedro Almendros
Summary: The synergy between metal catalysis and radical chemistry has enabled researchers to overcome previous limitations in reactions between allenols and sulfonylating reagents, leading to successful copper-catalyzed cascade cycloetherification/sulfonylation for the controlled preparation of specific products.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Qi Li, Zi-Lu Wang, Yun-He Xu
Summary: Copper-catalyzed 1,4-protosilylation and 1,4-protoborylation reactions of enynic orthoesters were developed. The enynic orthoesters, as precursors of unstable enynic esters, were used to produce functionalized 2,3-allenoate products. The asymmetric 1,4-protosilylation of enynic orthoesters with PhMe2Si-Bpin was also studied, and the chiral monopyridine imidazoline ligand exhibited high enantioselectivity.
CHINESE CHEMICAL LETTERS
(2023)
